A ring spinning machine can have an automatic roving bobbin changing device which travels along the bobbin cross bar or the machine frame and which draws a full roving bobbin from a storage magazine or storage location and puts it in a dispensing position in the spinning machine in place of an empty roving bobbin.
In the roving bobbin changing apparatus of German Open Patent Application No. 33 12 116 this storage magazine is provided in the automatic roving bobbin changing device so that the roving bobbin changing device carries its roving bobbin storage magazine with it. On account of its weight and its spatial requirements the capacity of this kind of storage location in its traveling roving bobbin changing device is limited. This requires frequent filling of the storage magazine during which the roving bobbin changing can not occur.
It is also known to suspend a row of stand-by roving bobbins from the bobbin cross bar of a ring spinning machine as taught in German Open Patent Application Nos. 32 10 329 and 32 40 822. These stand-by roving bobbins form a magazine fixed with respect to each dispensing position and can be used to replace empty bobbins either by hand or by an automatic roving bobbin changing device as needed (German Open Patent Application No. 32 08 677). Because of space considerations, each stand-by position is associated with a plurality, usually two sometimes three or four, dispensing positions.
When an automatic roving bobbin changing device moving along in the spinning machine acts on a dispensing position or feed position in which the associated stand-by position is already empty because of a change in this stand-by position due to another associated dispensing position, this automatic roving bobbin changing device can not perform its function at this site for lack of a full roving bobbin.